Proteoglycans are part of the extracellular matrix; they provide structure, viscosity and lubrication, and adhesiveness. they are composed of proteins conjugated to carbohydrate components called glycosaminoglycans. the glycosaminoglycan component makes up the majority of the mass of a proteoglycan. which of the following are possible components of glycosaminoglycans? select all that apply. determine which of the following statements about glycosaminoglycans are true. there is more than one true statement; select all the true statements. dermatan sulfate and keratan sulfate are examples of glycosaminoglycans. because glycosaminoglycans consist of only two residues, they generally have low molecular weights. dextran is an example of a glycosaminoglycan. glycosaminoglycans are heteropolysaccharides composed of repeating disaccharide units. the amino groups of the amino sugar derivatives provide a positive charge that offsets the negative charges from the sulfate or carboxylate groups.

Here’s what I find.

Explanation:

A. Dermatan sulfate and keratan sulfate are examples of glycosaminoglycans (GAGs). TRUE.

They are both long unbranched polymers in which the repeating unit is a disaccharide consisting of a uronic sugar and an N-acetylated amino sugar.

D. Glycosaminoglycans are heteropolysaccharides composed of repeating disaccharide units. TRUE.

A heteropolysaccharide contains two or more monosaccharides, and GAGs contain  a hexoseuronic acid and an N-acetylhexosamine.

B. FALSE. GAGs consist of only two residues, but they are the disaccharide units in a polymer chain that has a molecular weight greater

than 2.5 × 10^6 u.

C. FALSE. Dextran is a polysaccharide of glucose.

E. FALSE. The amino groups in the amino sugars are acetylated, so they are acetamide derivatives. Amides (Kb = 10^-15) are much less basic than amines (Kb = 10^-5), so they are not protonated.

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).